Prior to drilling operations, a drill rod must be secured in the chuck of a drill head assembly. Conventionally, workers use their hands to support, lift, and/or rotate a drill rod in a position that allows the chuck to threadingly engage the drill rod. Typically, a worker threads a mainline hoist plug onto a new rod. As the rod is lifted by the hoist, the worker guides an end of the new rod over a previous rod in the hole, and the chuck is rotated by hand to engage the threads of the drill rod. The chuck is then repositioned and rotated to apply sufficient torque to the rod to make the joint. Ideally, the workers will stabilize the drill rod such that the drill rod does not rotate with the chuck but is advanced axially within the chuck. However, in practice, the workers supporting the drill rod often fail to prevent rotation of the drill rod, and the workers also regularly fail to maintain the drill rod in alignment with the chuck. These issues create inefficiency in the process of engaging the drill rod with the chuck and frequently lead to worker injuries.
Some conventional attempts at addressing these problems include floating devices, such as spline/spring assemblies, and hydraulic float devices, such as feed cylinder valves. Both of these attempts allow axial translation during rotation. However, splined floating devices are expensive and heavy and can add to the overall length of the drill head assembly. It is not always practical to apply the force required to compress the springs of these floating devices before threading and/or unthreading the joint. Furthermore, because the drill rod is not always oriented parallel to the feed cylinder, use of hydraulic float devices is not always possible.
Additionally, due to the complexity of conventional rod loaders and rod carousels/magazines, these rod loaders and rod carousels/magazines cannot be retrofit to existing drill systems in a cost-effective manner. Moreover, these existing products only work with particular drill head and/or drill mast geometries.
Thus, there is a need in the pertinent art for devices and systems that reduce manual drill rod handling during threading and unthreading of drill rod joints. There is a further need in the pertinent art for devices and systems that enhance the ergonomics, safety, and productivity in drill rod handling.